ENBREL® (etanercept) is a dimeric fusion protein consisting of the extracellular ligand-binding portion of the human 75 kilodalton (p75) tumor necrosis factor receptor (TNFR) linked to the Fc portion of human IgG1. The Fc component of etanercept contains the CH2 domain, the CH3 domain and hinge region, but not the CH1 domain of IgG1. Etanercept is produced by recombinant DNA technology in a Chinese hamster ovary (CHO) mammalian cell expression system. It consists of 934 amino acids and has an apparent molecular weight of approximately 150 kilodaltons.

ENBREL® single-use prefilled syringes are available in 25 mg (0.51 mL of a 50 mg/mL solution of etanercept) and 50 mg (0.98 mL of a 50 mg/mL solution of etanercept) dosage strengths.

ENBREL® single-use prefilled SureClick® autoinjectors are available in 50 mg (0.98 mL of a 50 mg/mL solution of etanercept).

Administration of one 50 mg ENBREL® prefilled syringe or one ENBREL® SureClick autoinjector provides a dose equivalent to two 25 mg ENBREL® prefilled syringes or two multiple-use vials of lyophilized ENBREL®, when vials are reconstituted and administered as recommended.